Preparation and Characterization of Pickering Emulsions with Modified Okara Insoluble Dietary Fiber

Fermented insoluble fiber enhances the emulsifying property and bioaccessibility of essential oil emulsion with its whey protein isolate conjugates and chitosan

BACKGROUND

Using polysaccharide-protein conjugates to deliver essential oil has garnered widespread attention in the food industry. In this study, conjugates between insoluble dietary fibers (IDF) from Chenpi pomace and whey protein isolate (WPI) were first improved by fermentation, and then dual-layer Pickering emulsions were prepared by the conjugates and chitosan (CS) using layer-by-layer self-assembly technology and used for Chenpi essential oil (CEO) delivery.

RESULTS

Fermentation was found to enhance the Maillard reaction between IDF and WPI, and the emulsion controlled the release of CEO. Fermented IDF (FIDF) bound more WPI and the grafting degree increased by 54.1%, compared to the original IDF, due to the augmentation of FIDF specific surface area and the exposure of glucose, mannose, and galacturonic acid terminals. Furthermore, FIDF-WPI conjugates exhibited high thermal stability, hydrophobicity, and emulsifying properties, and the CEO-loaded dual-layer emulsions demonstrated uniform droplet size, strong storage stability, and excellent antioxidant activity. This effectively controlled the release of CEO and protected eight CEO components in gastrointestinal digestion, resulting in an increase of 167% in the bioaccessibility of CEO. These results can be attributed to the formation of a compact interfacial film composed of dense hydrophobic FIDF-WPI conjugates around the CEO droplets, the isolating effect of the improved three-dimensional structure formed by the FIDF-WPI-CS complexes, and the electrostatic repulsion between the emulsion droplets.

CONCLUSION

Fermentation can enhance the delivery of CEO in emulsions prepared with IDF-WPI conjugates and CS, and these findings contribute to the development of related functional foods. © 2025 Society of Chemical Industry.

Insoluble dietary fiber stabilized Pickering emulsions as novel food ingredients: Preparation, potential applications and future perspectives

Pickering emulsions (PEs) are valued in the food industry for their biocompatibility and stability. Insoluble dietary fiber (IDF), a sustainable and low-toxicity stabilizer derived from agricultural by-products, has shown great potential for food applications. This paper reviews advancements in IDF extraction and its use in creating IDF-based PEs (IDF-PEs). Key applications in the food sector include food packaging, 3D printing, fat substitution, bioactive delivery, and food stabilization. IDF's natural stabilizing properties and environmentally friendly extraction from agricultural waste are emphasized. While challenges remain regarding the stability and safety of IDF-PEs in complex food systems, their versatility and broad application potential make them a promising area of research. This study provides insights into developing sustainable, multifunctional food ingredients, aiming to expand the use of IDF-PEs and contribute to global sustainability goals.

Preparation of citrus fiber from lemon peel residue: Effects of structure and endogenous pectin components on emulsifying properties of citrus fiber

This study evaluated and compared the differences in structure and physicochemical properties between citrus fibers prepared after different degrees of pectin extraction and untreated citrus fibers. The results showed that the partial hydrolysis and release of internal pectin would cause the physical and chemical properties of citrus fibers to show a tendency to increase and then decrease with treatment time, with a steady increase in crystallinity and thermal stability. The water-holding capacity (15.81 g/g), swelling capacity (12.50 mL/g), and oil-holding capacity (3.33 g/g) of CF-5 h still remained noticeably higher than those of CF. The SEM results demonstrated that at the pectin extraction time of 5 h, the internal network structure of the cell wall of CF-5 h prepared at this time was maximized in terms of looseness. Meanwhile, the emulsion prepared from CF-5 h had the best emulsification properties, which were characterized by the smallest emulsion particle size(d4，3 = 10.40 μm), the best rheological properties, and excellent emulsion stability. Overall, the citrus fibers prepared after a certain degree of pectin extraction showed good performance in terms of physicochemical properties and emulsification performance.

Advancements in modifying insoluble dietary fiber: Exploring the microstructure, physicochemical properties, biological activity, and applications in food industry-A review

Recent research has primarily focused on strategies for modifying insoluble dietary fiber (IDF) to enhance its performance and functionality. IDF is obtained from various inexpensive sources and can be manipulated to alter its biological effects, making it possible to revolutionize food processing and nutrition. In this review, multiple IDF modification techniques are thoroughly examined and discussed, with particular emphasis on the resulting changes in the physicochemical properties, biological activities, and microstructure of the fiber. An extensive overview of the practical applications of modified IDF in food processing is provided. Our study aims to raise awareness about the vast possibilities presented by modified IDF and encourage further exploration and utilization of this field in the realm of food production.

Pickering Emulsion of Curcumin Stabilized by Cellulose Nanocrystals/Chitosan Oligosaccharide: Effect in Promoting Wound Healing

Background: The stabilization of droplets in Pickering emulsions using solid particles has garnered significant attention through various methods. Cellulose and chitin derivatives in nature offer a sustainable source of Pickering emulsion stabilizers. Methods: In this study, medium-chain triglycerides were used as the oil phase for the preparation of emulsion. This study explores the potential of cellulose nanocrystals (CNC) and shell oligosaccharides (COS) as effective stabilizers for achieving stable Pickering emulsions. Optical microscopy, CLSM, and Cyro-SEM were employed to analyze CNC/COS-Cur, revealing the formation of bright and uniform yellow spherical emulsions. Results: CLSM and SEM results confirmed that CNC/COS formed a continuous and compact shell at the oil-water interface layer, enabling a stable 2~3 microns Pickering emulsion with CNS/COS-Cur as an oil-in-water emulsion stabilizer. Based on FTIR, XRD, and SEM analyses of CNC/COS, along with zeta potential measurements of the emulsion, we found that CNC and COS complexed via electrostatic adsorption, forming irregular rods measuring approximately 200-300 nm in length. An evaluation of the DPPH radical-scavenging ability demonstrated that the CNC/ COS-Cur Pickering emulsion performed well in vitro. In vivo experiments involving full-thickness skin excision surgery in rats revealed that CNC/COS-Cur facilitated wound repair processes. Measurements of the MDA and SOD content in healing tissues indicated that the CNC/COS-Cur Pickering emulsion increased SOD levels and reduced MDA content, effectively countering oxidative stress-induced damage. An assessment based on wound-healing rates and histopathological examination showed that CNC/COS-Cur promoted granulation tissue formation, fibroblast proliferation, angiogenesis, and an accelerated re-epithelialization process within the wound tissue, leading to enhanced collagen deposition and facilitating rapid wound-healing capabilities. An antibacterial efficacy assessment conducted in vitro demonstrated antibacterial activity.

Effect of structural characteristics on the physicochemical properties and functional activities of dietary fiber: A review of structure-activity relationship

Dietary fibers come from a wide range of sources and have a variety of preparation methods (including extraction and modification). The different structural characteristics of dietary fibers caused by source, extraction and modification methods directly affect their physicochemical properties and functional activities. The relationship between structure and physicochemical properties and functional activities is an indispensable basic theory for realizing the directional transformation of dietary fibers' structure and accurately regulating their specific properties and activities. In this paper, since a brief overview about the structural characteristics of dietary fiber, the effect of structural characteristics on a variety of physicochemical properties (hydration, electrical, thermal, rheological, emulsifying property, and oil holding capacity, cation exchange capacity) and functional activities (hypoglycemic, hypolipidemic, antioxidant, prebiotic and harmful substances-adsorption activity) of dietary fiber explored by researchers in last five years are emphatically reviewed. Moreover, the future perspectives of structure-activity relationship are discussed. This review aims to provide theoretical foundation for the targeted regulation of properties and activities of dietary fiber, so as to improve the quality of their applied products and physiological efficiency, and then to realize high value utilization of dietary fiber resources.

Food-Grade Oil-in-Water (O/W) Pickering Emulsions Stabilized by Agri-Food Byproduct Particles

In recent years, emulsions stabilized by solid particles (known as Pickering emulsions) have gained considerable attention due to their excellent stability and for being environmentally friendly compared to the emulsions stabilized by synthetic surfactants. In this context, edible Pickering stabilizers from agri-food byproducts have attracted much interest because of their noteworthy benefits, such as easy preparation, excellent biocompatibility, and unique interfacial properties. Consequently, different food-grade particles have been reported in recent publications with distinct raw materials and preparation methods. Moreover, emulsions stabilized by solid particles can be applied in a wide range of industrial fields, such as food, biomedicine, cosmetics, and fine chemical synthesis. Therefore, this review aims to provide a comprehensive overview of Pickering emulsions stabilized by a diverse range of edible solid particles, specifically agri-food byproducts, including legumes, oil seeds, and fruit byproducts. Moreover, this review summarizes some aspects related to the factors that influence the stabilization and physicochemical properties of Pickering emulsions. In addition, the current research trends in applications of edible Pickering emulsions are documented. Consequently, this review will detail the latest progress and new trends in the field of edible Pickering emulsions for readers.

Optimization of Mixed Fermentation Conditions of Dietary Fiber from Soybean Residue and the Effect on Structure, Properties and Potential Biological Activity of Dietary Fiber from Soybean Residue

Soybean residue is a by-product of soybean product production that is wasted unreasonably at present. Accomplishing the efficient utilization of soybean residue can save resources. A composite microbial system was constructed using lactic acid bacteria (LAB) and Saccharomyces cerevisiae (SC), and modified soybean residue was prepared by solid fermentation. In order to explore the value of modified soybean residue as a food raw material, its physical and chemical properties, adsorption properties, and antioxidant properties were studied. The results showed that the soluble dietary fiber (SDF) yield of mixed fermentation (MF) increased significantly. Both groups of soybean residues had representative polysaccharide infrared absorption peaks, and MF showed a looser structure and lower crystallinity. In terms of the adsorption capacity index, MF also has a higher adsorption capacity for water molecules, oil molecules, and cholesterol molecules. In addition, the in vitro antioxidant capacity of MF was also significantly higher than that of unfermented soybean residue (UF). In conclusion, our study shows that mixed fermentation could increase SDF content and improve the functional properties of soybean residue. Modified soybean residue prepared by mixed fermentation is the ideal food raw material.

Characterization of Physicochemical Properties of Oil-in-Water Emulsions Stabilized by Tremella fuciformis Polysaccharides

In this paper, emulsions stabilized by Tremella fuciformis polysaccharides (TFP) were prepared and the physiochemical properties were assessed. Results showed that the TFP emulsions illustrated the highest emulsifying activity (EAI) and emulsifying stability (ESI) when the concentration of TFP and oil were 0.8% and 10% (wt%). The higher pH value was in favor of the emulsifying properties, while the addition of NaCl impaired the stability, and the greater the concentration, the lower the EAI and ESI. Besides, the emulsifying and rheological properties and stability analysis were evaluated in comparison with gum arabic, pectin, and carboxymethyl cellulose emulsions. It was discovered that TFP illustrated better storage and freeze-thaw stability, which was proved by the result of zeta-potential and particle size. The rheological measurement revealed that all the emulsions behaved as pseudoplastic fluids, while TFP displayed a higher viscosity. Meanwhile, TFP emulsions tended to form a more stable network structure according to the analysis of the parameters obtained from the Herschel–Bulkley model. FTIR spectra suggested that the O-H bond could be destructed without the formation of new covalent bonds during the emulsion preparation. Therefore, this study would be of great importance for the research of emulsions stabilized by TFP as a natural food emulsifier.